The purpose of this core is to provide infrastructure resources for projects in the grant utilizing Magnetic Resonance Imaging, and to develop resources that may be shared for the current projects as well as future projects relevant to developmental disorders in fronto-striatal circuits. There will be four primary components of the Imaging Core: a technical sub-core, focused on testing and ensuring high image quality and integrating new technological developments developments including novel pulse sequences, parallel imaging technology, a head gradient set, rapid reconstruction algorithms, and simultaneous EEG/fMRI,as well as supporting structural MRi and DTI acqiuisition. A design and analysis sub-core will provide expertise for designing and implementing fMRi experiments, and analysis of fMRI, structural MRI and DTI data, and analysis. A behavioral training/desensitization unit will use a simulated MRi environment with biofeedback to desensitization pediatric subjects to the environment and track head motion to maximize the likelihood of successfully scanning difficult populations. Finally, an analysis and databasing unit will conduct fMRI analyses for CIDAR projects and manage and maintain a structural MRI database. Structural and DTI data acquired in the Imaging core will feed into all of the human projects (1,3,and 4) to test specific hypothesis of structural and functional connectivity in front-striatal circuits. The infrastructure resources provided by the Imaging Core is integral to projects 3 and 4 and benefits subjects entering Project 1;these resources will be available for future pediatric imaging studies that may access the UCLA CIDAR in future years. An imaging core dedicated to promoting research into the neurobiology of ADHD and Tourette's will enable us to tackle some of the more difficult problems in pediatric imaging, namely, the technical difficulties in image acquisition in orbito-frontal retgions;analysis of developing brains that may contain structural differences or abnormalities;variability in brain development in children;and practical difficulties in scanning children with disorders of cognitive control. Having core resources at every stage of the imaging study, from design and image acquisition through data analysis, will enable investigators who are not imaging experts to apply these methods to other developmental disorders, and will provide resources to evaluate the effects of new treatments, both behavioral and pharmacological, on brain function in developmental disorders.